B-cell Numbers Research Articles

Prodromal / Pre-Leukemic Acute Leukemia of B-Lymphoblasts in 7 Adult Patients

Background: Prodromal/pre-leukemic acute leukemia is rare, mostly described in childhood B-lymphoblastic leukemia (B-ALL), with its initial presentation confused with aplastic anemia (AA). Findings reported in pediatric prodromal/pre-leukemic B-ALL include female preponderance, bone marrow (BM) fibrosis and uniform hypocellularity, and transient recovery. Reports in adults are rarer still. We conducted a retrospective review of adult patients we diagnosed with B-ALL and mixed phenotype acute leukemia with B-lymphoid and myeloid components (MPAL-B/myeloid) with prodromal/pre-leukemic manifestations. We sought to identify common clinical features, peripheral blood (PB) and BM morphology, diagnostic considerations, and clinical follow-up (whenever available) to aid in improved recognition in the adult setting. Methods: Patients with unusual presentations preceding overt acute leukemia were identified from pathology and clinical records from our institution from 2010-2020. These include (a) incidental PB blasts and partial BM-based disease, followed by spontaneous, transient regression (STR); (b) pancytopenia with rare to absent PB blasts and unexpected detection of BM-based blasts (10% or lower), compatible with aleukemic prodrome (AP) cases; (c) pancytopenia without PB blasts yet unexpected excess BM-based blasts (50% or greater) followed by marked reduction of BM-based blasts (compared to initial BM) despite absence of treatment (AP-->SR). BM pathology during prodromal/pre-leukemic phases were reviewed to identify key morphologic features. Results: Seven patients were identified (4 M, 3 F; age range 20-75 years), including one previously described by our group (Table 1). All were of Hispanic ethnicity. They displayed a broad range of symptoms including fatigue, fevers, throat pain, and weight loss. Initial presentations were STR in 3, AP in 2, and AP-->SR in 2. Although variably cellular, all BM trephine biopsies in prodromal/pre-leukemic phase had at least focal hypocellularity with stromal damage, characterized by granular to fibrillary stroma, striking cellular dropout, and multiloculated fat cells with fibrinoid appearance. Relative erythroid hyperplasia was seen in 4, while dyserythropoiesis and dysmegakaryocytopoiesis were both observed in 2 cases, raising concern for myelodysplastic syndrome (MDS). AA and MDS were, in some cases, seriously considered in the initial differential diagnosis. Because of low level BM blasts at initial presentation in most (5/7), definitive lineage designation was sometimes challenging. Furthermore, flow cytometric data was limited and IHC stained only a sparse number of immature B-cells; thus normal precursor B-cell (hematogone) hyperplasia was a strong possibility. Workup in 2 cases during low numbers of BM-based blasts or spontaneous blast reduction (cases #6 and #7, respectively) revealed T-cell clones on PCR/NGS testing. In STR and AP cases, the disease proceeded from initial presentation to overt leukemia within a fairly short interval (range 1.5 - 7.0 months; median 2.5). Final diagnosis in the majority of cases (6/7) was B-ALL, with one case of MPAL-B/myeloid. Conclusion: Herein we describe a series of 7 adult prodromal/pre-leukemic cases of B-lymphoblasts (6 B-ALL; 1 MPAL-B/myeloid) with a variety of clinical presentations. In contrast to the female-predominant pediatric prodromal B-ALLs, most of our adult cases occurred in males. Given pancytopenia, relatively low numbers, and difficulty in assigning blast lineage, diagnostic considerations initially included MDS, AA, and hematogone hyperplasia with marrow regeneration. Key morphologic features that favored a prodromal/pre-leukemic case of B-lymphoblasts over MDS or AA were profound stromal damage and expansion (albeit low numbers) of immature B-cells - findings that would be unusual in low-grade MDS and AA. Intriguingly, in 2 of our cases, T-cell clones detected on PCR testing during low blast levels may indicate an immunologic role of T-cells in transiently reducing blasts in prodromal acute leukemia, as previously suggested by Zimmermannova and colleagues (Haematol2017;102:e225-228). Regardless of whether patients experienced STR, AP, or AP-->SR, close clinical follow-up is advised, as progression to overt leukemia occurs within a relatively short time frame (median of 2.5 months in our series). Disclosures No relevant conflicts of interest to declare.

RNase H-dependent PCR enables highly specific amplification of antibody variable domains from single B-cells.

Immunization-based antibody discovery platforms require robust and effective protocols for the amplification, cloning, expression, and screening of antibodies from large numbers of B-cells in order to effectively capture the diversity of an experienced Ig-repertoire. Multiplex PCR using a series of forward and reverse primers designed to recover antibodies from a range of different germline sequences is challenging because primer design requires the recovery of full length antibody sequences, low starting template concentrations, and the need for all the primers to function under the same PCR conditions. Here we demonstrate several advantages to incorporating RNase H2-dependent PCR (rh-PCR) into a high-throughput, antibody-discovery platform. Firstly, rh-PCR eliminated primer dimer synthesis to below detectable levels, thereby eliminating clones with a false positive antibody titer. Secondly, by increasing the specificity of PCR, the rh-PCR primers increased the recovery of cognate antibody variable regions from single B-cells, as well as downstream recombinant antibody titers. Finally, we demonstrate that rh-PCR primers provide a more homogeneous sample pool and greater sequence quality in a Next Generation Sequencing-based approach to obtaining DNA sequence information from large numbers of cloned antibody cognate pairs. Furthermore, the higher specificity of the rh-PCR primers allowed for a better match between native antibody germline sequences and the VL/VH fragments amplified from single B-cells.

Haematopoietic PI3-kinase delta deficiency profoundly impairs regulatory T-cell biology and thereby protection against atherosclerosis

Abstract Introduction and purpose Atherosclerosis is a chronic inflammatory disease of arteries, critically involving leukocytes like macrophages as well as T and B lymphocytes. Macrophages are major drivers of disease through the ingestion of lipoproteins, foam cell formation, and secretion of inflammatory mediators. Although macrophages outnumber other leukocytes in atherosclerotic plaques, T and B cells can shape the course of disease by promoting or mitigating inflammatory responses. Leukocytes highly express the phosphoinositide 3-kinase isoform delta (PI3Kd), exerting a key role in the regulation of immune responses including activation, proliferation, differentiation, and effector functions. Therefore, PI3Kd represents a promising target for the modulation of inflammatory diseases. Consequently, we aimed to analyse the role of PI3Kd in leukocytes during atherogenesis. Methods and results To investigate the role of PI3Kd in atherosclerosis, bone marrow from PI3Kd−/− or PI3Kd+/+ mice was transplanted into LDLR−/− mice. After a 6-weeks-challenge by high fat diet, PI3Kd−/− recipient LDLR−/− mice displayed profoundly impaired CD4+ and CD8+ T-cell numbers, CD4+ T-cell activation, CD4+ effector T-cell differentiation, and proatherogenic CD4+ T-helper (Th) 1 responses in para-aortic lymph nodes and spleen compared with PI3Kd+/+ transplanted controls. Surprisingly, the net effect of PI3Kd deficiency was a substantial increase of aortic inflammation and atherosclerosis in LDLR−/− mice. Whereas plaque content and functions of macrophages including foam cell formation, efferocytosis, and cytokine secretion remained unaffected, haematopoietic PI3Kd ablation strongly reduced mature B cells and serum immunoglobulins in LDLR−/− mice. Importantly, PI3Kd deficiency severely impaired numbers and immunosuppressive functions of regulatory CD4+ T cells (Tregs) in spleen, para-aortic lymph nodes, and plaques of LDLR−/− mice. Consequently, adoptive transfer of PI3Kd+/+ Tregs fully constrained the plaque burden in PI3Kd−/− transplanted LDLR−/− mice without affecting B-cell numbers and serum immunoglobulins, whereas adoptively transferred PI3Kd−/− Tregs were unable to relieve atherosclerosis progression. Conclusions Here, we demonstrate that PI3Kd plays a crucial role in Tregs, Th1 cells, and B cells during atherogenesis. Lack of PI3Kd signalling specifically in atheroprotective Treg responses outplays its impact on proatherogenic Th1 and B-cell responses, thus leading to aggravated atherosclerosis. Hence, PI3Kd is a key regulator of Treg biology and thereby protects against atherosclerosis. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Marga and Walter Boll Foundation

ТЕРАПЕВТИЧЕСКАЯ ЭФФЕКТИВНОСТЬ ЭНТРИКИМА ПРИ ЭНЗООТИЧЕСКОЙ ПНЕВМОНИИ СВИНЕЙ

The number of T-lymphocytes in the subacute course decreases to 28.9±1.4% and in the chronic course it increased to 69.1±1.2%. However, against the background of lymphopenia, the absolute value of lymphocytes also decreased to 0.70±0.038·109 /l in the acute form of the disease. In chronic pneumonia, the number of lymphocytes was at the level of 0.44±0.04·109 /l. The T-x/T-c ratio also changed, depending on the form of enzootic pneumonia. With subacute – 1.7, and with chronic – 2.28. The entrikim treatment of piglets with a subacute course carried out for 7 days and a blood test 5 days after the implementation of sanitation showed that the number of Tlymphocytes increased twofold to 1.40±0.04·109 /l, while the Tx/Tc ratio was 2, 28, which corresponds to the physiological norm. After the treatment of piglets with a chronic course, all analyzed parameters characterizing the state of T-cell immunity testified to its normal functioning. A decrease in the total number of T-lymphocytes, individual EAK populations, indicate a depressive state of lymphopoiesis. A decrease in the number of T-lymphocytes to 0.44±0.04·109 /l in chronic course up to indicates a deep suppression of cellular immunity. In the subacute form of the disease, the number of B-lymphocytes decreased to 14.07±1.92%, but increased to 32.64±0.3% in the chronic course. But against the background of lymphopenia in subacute form, the absolute value of lymphocytes decreased to 0.36±0.04·109 /l, and in chronic lymphopenia to 0.20±0.06·109 /l. In the subacute form of the disease, the content of Ig A (1.49±0.03 mg/ml) and Ig G (1.39±0.02 mg/ml) does not differ from healthy animals, but a low level of Ig M (11.0±0.12 mg/ml) indicates a negative effect of mycoplasmas on humoral immunity. In chronic course, there is a sharp decrease (by 30%) Ig A to 1.49±0.03 and vice versa, a sharp increase by 30% in the Ig G content (11.8±011 mg/ml). After treatment of piglets with a subacute course of the disease, the number of B-lymphocytes increased by 2 times, and after treatment with m with a chronic course of the disease, by 3.5 times to 0.70±0.04·109 /L. The use of entrikim has a positive effect on humoral immunity, as the amount of Ig G increases by 45%. The therapeutic efficacy of entrikim increases due to the synergistic interaction of enrofloxacin, trimethoprim and tilmicosin phosphate. The therapeutic efficacy of entrikim in the subacute course was 90.7%, and in the chronic one – 74.4%.

Biological effects of inhaled hydraulic fracturing sand dust. VIII. Immunotoxicity

Hydraulic fracturing (“fracking”) is a process used to enhance retrieval of gas from subterranean natural gas-laden rock by fracturing it under pressure. Sand used to stabilize fissures and facilitate gas flow creates a potential occupational hazard from respirable fracking sand dust (FSD). As studies of the immunotoxicity of FSD are lacking, the effects of whole-body inhalation (6 h/d for 4 d) of a FSD, i.e., FSD 8, was investigated at 1, 7, and 27 d post-exposure in rats. Exposure to 10 mg/m3 FSD 8 resulted in decreased lung-associated lymph node (LLN) cellularity, total B-cells, CD4+ T-cells, CD8+ T-cells and total natural killer (NK) cells at 7-d post exposure. The frequency of CD4+ T-cells decreased while the frequency of B-cells increased (7 and 27 d) in the LLN. In contrast, increases in LLN cellularity and increases in total CD4+ and CD8+ T-cells were observed in rats following 30 mg/m3 FSD 8 at 1 d post-exposure. Increases in the frequency and number of CD4+ T-cells and NK cells were observed in bronchial alveolar lavage fluid at 7-d post-exposure (10 mg/m3) along with an increase in total CD4+ T-cells, CD11b + cells, and NK cells at 1-day post-exposure (30 mg/m3). Increases in the numbers of B-cells and CD8+ T-cells were observed in the spleen at 1-day post 30 mg/m3 FSD 8 exposure. In addition, NK cell activity was suppressed at 1 d (30 mg/m3) and 27 d post-exposure (10 mg/m3). No change in the IgM response to sheep red blood cells was observed. The findings indicate that FSD 8 caused alterations in cellularity, phenotypic subsets, and impairment of immune function.

The Infection of Leukemia in Children with hormone variation in Baghdad Patients

The purpose of the current study was to find out the reasons that lead to a continuous Increase in the injury of children (0-14 years) with leukemia. There is no information to support the mother s exposure to prenatal accidents or the extent 0f their impact on the fetus. Therefore, the study suggested the effect of some environmental factors such as pollution in Baghdad and them are genetic. The study was conducted on 30 children with acute leukemia divided into two subgroups 15 male and 15 females, the control group also consisted of 30 children and divided into two subgroups 15 male and 15 females. The results showed a large numbers of acute lymphoblast leukemia B-cells (ALL)in the peripheral blood smear of infected children with leukemia. The level of erythropoietin showed significant variation in the groups that were included in the study where the EPO level in the infected children was (82.476±7.435mIU/ml), while the EPO level in the uninfected children was (12.321±1.315mIU/ml). the study also Show that there were significant differences in the levels of EPO in children from males with an infection (85.672±1.127 mIU/ml) compared to children of uninfected males (12.869±1.623mIU/ml). This also applies to children of infected females (72.351±9.216mIU/ml) compared to Children of uninfected females (11.672±0.632 mIU/ml).

PKC-\u03b4 deficiency in B cells displays osteopenia accompanied with upregulation of RANKL expression and osteoclast\u2013osteoblast uncoupling

PKC-δ is an important molecule for B-cell proliferation and tolerance. B cells have long been recognized to play a part in osteoimmunology and pathological bone loss. However, the role of B cells with PKC-δ deficiency in bone homeostasis and the underlying mechanisms are unknown. We generated mice with PKC-δ deletion selectively in B cells by crossing PKC-δ-loxP mice with CD19-Cre mice. We studied their bone phenotype using micro-CT and histology. Next, immune organs were obtained and analyzed. Western blotting was used to determine the RANKL/OPG ratio in vitro in B-cell cultures, ELISA assay and immunohistochemistry were used to analyze in vivo RANKL/OPG balance in serum and bone sections respectively. Finally, we utilized osteoclastogenesis to study osteoclast function via hydroxyapatite resorption assay, and isolated primary calvaria osteoblasts to investigate osteoblast proliferation and differentiation. We also investigated osteoclast and osteoblast biology in co-culture with B-cell supernatants. We found that mice with PKC-δ deficiency in B cells displayed an osteopenia phenotype in the trabecular and cortical compartment of long bones. In addition, PKC-δ deletion resulted in changes of trabecular bone structure in association with activation of osteoclast bone resorption and decrease in osteoblast parameters. As expected, inactivation of PKC-δ in B cells resulted in changes in spleen B-cell number, function, and distribution. Consistently, the RANKL/OPG ratio was elevated remarkably in B-cell culture, in the serum and in bone specimens after loss of PKC-δ in B cells. Finally, in vitro analysis revealed that PKC-δ ablation suppressed osteoclast differentiation and function but co-culture with B-cell supernatant reversed the suppression effect, as well as impaired osteoblast proliferation and function, indicative of osteoclast–osteoblast uncoupling. In conclusion, PKC-δ plays an important role in the interplay between B cells in the immune system and bone cells in the pathogenesis of bone lytic diseases.

Expansion of plasmablasts and loss of memory B cells in peripheral blood from COVID-19 patients with pneumonia.

Studies on the interactions between SARS-CoV-2 and humoral immunity are fundamental to elaborate effective therapies including vaccines. We used polychromatic flow cytometry, coupled with unsupervised data analysis and principal component analysis (PCA), to interrogate B cells in untreated patients with COVID-19 pneumonia. COVID-19 patients displayed normal plasma levels of the main immunoglobulin classes, of antibodies against common antigens or against antigens present in common vaccines. However, we found a decreased number of total and naïve B cells, along with decreased percentages and numbers of memory switched and unswitched B cells. On the contrary, IgM+ and IgM- plasmablasts were significantly increased. In vitro cell activation revealed that B lymphocytes showed a normal proliferation index and number of dividing cells per cycle. PCA indicated that B-cell number, naive and memory B cells but not plasmablasts clustered with patients who were discharged, while plasma IgM level, C-reactive protein, D-dimer, and SOFA score with those who died. In patients with pneumonia, the derangement of the B-cell compartment could be one of the causes of the immunological failure to control SARS-Cov2, have a relevant influence on several pathways, organs and systems, and must be considered to develop vaccine strategies.

The application of CytoDiff for the differential diagnosis of reactive and tumor lymphocytosis.

CytoDiff reagent was developed to optimize the performance of a WBC differential evaluation. It determines the main population of white blood cells by the expression of linear markers. One of the additional possibilities of using CytoDiff is the differential diagnosis of reactive and tumor lymphocytosis. We studied peripheral blood samples of 76 patients of the All-Russian Central Research Center A.M. Nikiforova EMERCOM of Russia with absolute lymphocytosis of more than 3,0x109/l. The control group included 26 practically healthy people. All performed a clinical blood test on a 5Diff hematology analyzer with smear microscopy, and determination of leukocyte populations by phenotype using CytoDiff. Reference intervals were determined for subpopulations of lymphocytes using CytoDiff. An algorithm has been developed for evaluating the results obtained when determining leukocyte populations by phenotype using CytoDiff for differential diagnosis of reactive and tumor lymphoproliferation. To detect B-cell lymphoproliferative diseases, the use of a cut-off value of 13% or more of the number of leukocytes is optimal. At low values of the relative number of B-lymphocytes, it is important to take into account the results of microscopy of blood smears. If atypical mononuclear cells are absent in smears, then additional clinical and laboratory studies are necessary to establish the cause of lymphocytosis, including phenotyping of peripheral blood lymphocytes to exclude T-cell lymphoproliferative diseases. The expediency of using the CytoDiff reagent for the differential diagnosis of the reactive and tumor nature of lymphocytosis is shown. Already at the stage of primary screening studies, the use of CytoDiff makes it possible to efficiently collect blood samples from patients with possible lymphoproliferative diseases, which significantly reduces the time required for a diagnostic search.

Increased antiviral response in circulating lymphocytes from hypogammaglobulinemia patients.

B cells play a crucial role during rhinovirus (RV) infections by production of virus-neutralizing antibodies. A main feature of common variable immunodeficiency (CVID) is hypogammaglobulinemia (HG). HG patients have severely reduced levels of antibody-producing B cells and suffer from prolonged virus infections. Here, we addressed whether antiviral response of peripheral blood lymphocytes differs between HG patients and healthy individuals during natural RV infection. Using fluorescence-activated cell sorting, B-cell subsets were analyzed. Simultaneously, CD19+B cells, CD14+monocytes, and CD3+T cells were sorted from frozen peripheral blood mononuclear cells from 11 RV-infected hypogammaglobulinemia patients, 7 RV-infected control subjects, and 14 noninfected control subjects. Real-time PCR was used to study expression of antiviral genes. A pan-RV PCR was used to detect RV genome in all samples. In HG patients, total B-cell numbers, as well as IgA+and IgG+switched memory B cells, were reduced while naïve B cells and T cells were increased. STAT1 expression was increased in HG patients compared to controls in all lymphocyte subsets analyzed. The expression of antiviral genes IFITM1 and MX1 correlated with STAT1 expression in B cells and monocytes. RV RNA was found in 88.9% of monocytes from infected HG patients, 85.7% of monocytes from infected controls, and 7.1% of monocytes from uninfected controls. We demonstrate an increased antiviral response in B cells and monocytes in HG patients and their correlation with STAT1 expression. Monocytes of infected HG patients and infected non-HG controls carry RV RNA.

Clinical and experimental studies of immunо-infl ammatory mechanisms of anthracosilicosis formation

Introduction. In the structure of occupational diseases of employees of the main professions of the coal industry, respiratory diseases are widespread, in the process of formation of which the key role belongs to the immune system of the body. Early manifestations of the development of professional pathology, as a rule, remain unnoticed, and therefore there is a need to study the pathogenetic mechanisms underlying its formation, not only in clinical, but also in experimental conditions, allowing to assess the premorbid state of the body for timely diagnosis and treatment and prevention.The aim of the study is to study the immune-infl ammatory mechanisms of anthracosilicosis formation on the basis of clinical and experimental studies.Materials and methods. We examined 204 miners working in underground conditions with a signifi cant dustiness of workplaces exceeding the maximum permissible concentration by 10 or more times. Th e main group consisted of 115 workers with a previously established diagnosis of “anthracosilicosis”. Th e comparison group was formed from 89 miners without a diagnosis of respiratory pathology, working in similar sanitary conditions. To assess the dynamics of immuno-infl ammatory mechanisms in the experiment, modeling of dust pathology of the lungs was performed on 310 white male laboratory rats (220-experimental and 90 — control).Results. In patients with anthracosilicosis, the development of immune failure of humoral immunity mechanisms was revealed, which was manifested by a signifi cant decrease in the level of serum IgG against the background of an increase in the absolute and relative number of B-lymphocytes. Th e formation of anthracosilicosis is characterized by the active development of the immuno-infl ammatory process (an increase in the level of pro-infl ammatory cytokines and proteins of the acute phase of infl ammation), the severity of which increases when the disease is complicated by respiratory failure. Activation of the synthesis of anti-infl ammatory IL-4, which is a powerful inhibitor of macrophage infl ammation and slows down the processes of fi brosis in the bronchopulmonary system, acts as a protective mechanism that prevents the formation of respiratory failure in miners with anthracosilicosis. Experimental modeling of anthracosilicosis revealed phase changes in the immune response. In the early period of exposure to dust factor was observed activation of humoral (increased level of all classes of immunoglobulins) and the subsequent development of the inflammatory process (increased concentrations of acute phase proteins of inflammation) in the background of the balance between subpopulations of T-lymphocytes to ensure proper development of protective immune response. Long-term intake of antigen was characterized by violations of humoral immunity, the predominance of cell-type reactions and the chronization of the infl ammatory process.Conclusions. Th e study of immuno-infl ammatory mechanisms of anthracosilicosis formation in clinical and experimental conditions indicates the activation of urgent adaptation and maintenance of compensatory and adaptive reactions of the body in the early period of contact with dust antigen. Th e chronic form of anthracosilicosis is characterized by an imbalance of regulatory mechanisms, ineffi ciency of local immunity and the intensive development of generalized immune infl ammation, which increases with the addition of infection and complication of respiratory failure.

Immune reconstitution in children following chemotherapy for acute leukemia.

Although survival rates for pediatric acute lymphoblastic leukemia are now excellent, this is at the expense of prolonged chemotherapy regimens. We report the long‐term immune effects in children treated according to the UK Medical Research Council UKALL 2003 protocol. Peripheral blood lymphocyte subsets and immunoglobulin levels were studied in 116 participants, at six time points, during and for 18‐month following treatment, with 30‐39 patients analyzed at each time point.Total lymphocytes were reduced during maintenance chemotherapy and remained low 18 months following treatment completion. CD4 T cells remained significantly reduced 18 months after treatment, but CD8 cells and natural killer cells recovered to normal values. The fall in naïve B‐cell numbers during maintenance was most marked, but numbers recovered rapidly after cessation of treatment. Memory B cells, particularly nonclass‐switched memory B cells, remained below normal levels 18 months following treatment. All immunoglobulin subclasses were reduced during treatment compared to normal values, with IgM levels most affected.This study demonstrates that immune reconstitution differs between lymphocyte compartments. Although total B‐cell numbers recover rapidly, disruption of memory/naïve balance persists and T‐cell compartment persist at 18 months. This highlights the impact of modern chemotherapy regimens on immunity, and thus, infectious susceptibility and response to immunization.

COVID-19 and Cushing's syndrome: recommendations for a special population with endogenous glucocorticoid excess

COVID-19 and Cushing's syndrome: recommendations for a special population with endogenous glucocorticoid excess

Половые различия морфофункциональных изменений иммунной системы у крыс Вистар разных возрастных групп при экспериментальной эндотоксинемии

Objective. The aim was revealing gender differences in morphological and functional changes of lymphoid organs (thymus and spleen), changes of cytokine production and subpopulation composition of peripheral blood lymphocytes in Wistar rats of three age groups with endotoxemia. Materials and methods. We used male and female Wistar rats of three age groups: newborns, prepubertal and sexually mature adult rats. A day after the injection of 15 mg/kg of O26:B6 E. coli lipopolysaccharide (LPS), the volume fraction of the functional zones of the thymus and spleen, the number of AnnexinV + apoptotically dying cells in the thymus, the relative and absolute number of lymphocyte subpopulations (CD3+CD4+, CD3+CD8a+, CD4+CD25+Foxp3+, CD3-CD45R+) in peripheral blood and ex vivo production of IL-2, IL-4, IFN-γ and TNF-α were estimated. Results. Sex differences in the response of the immune system after the LPS injection in different age periods are expressed differently: in the neonatal period, there is immunosuppression in females (decrease in the ex vivo production of IL-2, TNF-α and IFN-γ), and there is activation of pro-inflammatory reactions in males (increase in ex vivo production of IL-2 and TNF-α). As compared with other age periods at prepubertal age, LPS-induced immunological disorders are more pronounced, and gender differences are minimal and related only to the number of T-regulatory and B-lymphocytes. In the adults, the LPS-induced immunosuppression is most pronounced in males - they have a decrease in the production of all the cytokines studied and a decrease in the number of cytotoxic and regulatory T-lymphocytes and B-cells. Conclusion. Thus, in each of the studied age periods - newborn, prepubertal and adult, the sexual differences in the immune system reactions are expressed differently and, apparently, these differences are determined by the content of sex steroid hormones, the concentration of which varies with age.

Influence of cadmium on the cellular part of the immune system of young cattle

The article presents the results of research on the effect of cadmium load on the body of young cattle. The negative effect of Cadmium on the liver causes a wide range of pathological changes at different levels of its organization. The impact of heavy metals on the immune system is particularly significant, because it performs a leading role in maintaining health and is recognized as one of the most sensitive to adverse factors, even in relatively low concentrations. The aim of the study was to investigate the influence of cadmium on the cellular part of the immune system of young cattle. The research was carried out on 10 bulls of six months of age, Ukrainian black-and-white dairy breed, which were formed into 2 groups of 5 animals each: control and experimental. The bulls of the control group were on a normal diet. Animals of the experimental group were administered cadmium chloride at a dose of 0.04 mg/kg body weight of the animal. It was found that feeding bulls with a diet of cadmium chloride, the number of B-lymphocytes on the 5th day of the experiment was 17.54 ± 0.95 %. The lowest number of B-lymphocytes was on the 20th day of testing – 15.12 ± 0.37 %. The study of the number of T-lymphocytes shows that at the beginning of analysis the number of T-lymphocytes in the blood of animals of the control and experimental groups ranged from 40.70 ± 3.62 and 40.85 ± 2.54 %. Subsequently, the number of T-lymphocytes in the blood of the experimental group began to decline. The lowest number of T-lymphocytes was in the experimental group of animals on the 20th day of the research, compared with the control group, this figure decreased by 3.63 %. The state of immunity of animals under cadmium load significantly depends on the ratio of T-helpers to T-suppressors. It was found that the immunoregulatory index of blood of bulls of the experimental group probably decreased from 10 days of the research. The number of T-helper lymphocytes in the blood of the experimental group of bulls under cadmium loading is probably reduced by 15, 20 and 30 days of testing. A probable increase in the number of T-suppressors was noted in the bull's blood of the experimental group on the 20th day of the research. Immunoglobulins of different classes are crucial among bull’s serum proteins under cadmium loading. The concentration of immunoglobulins in the blood under cadmium load decreased by 15.9 % relative to the control group on the 20th day of analysis.

Cxcl12 Deletion in Mesenchymal Cells Increases Bone Turnover and Attenuates the Loss of Cortical Bone Caused by Estrogen Deficiency in Mice.

CXCL12 is abundantly expressed in reticular cells associated with the perivascular niches of the bone marrow (BM) and is indispensable for B lymphopoiesis. Cxcl12 promotes osteoclastogenesis and has been implicated in pathologic bone resorption. We had shown earlier that estrogen receptor α deletion in osteoprogenitors and estrogen deficiency in mice increase Cxcl12 mRNA and protein levels in the BM plasma, respectively. We have now generated female and male mice with conditional deletion of a Cxcl12 allele in Prrx1 targeted cells (Cxcl12∆Prrx1 ) and show herein that they have a 90% decrease in B lymphocytes but increased erythrocytes and adipocytes in the marrow. Ovariectomy increased the expression of Cxcl12 and B-cell number in the Cxcl12f/f control mice, but these effects were abrogated in the Cxcl12∆Prrx1 mice. Cortical bone mass was not affected in Cxcl12∆Prrx1 mice. Albeit, the cortical bone loss caused by ovariectomy was greatly attenuated. Most unexpectedly, the rate of bone turnover in sex steroid-sufficient female or male Cxcl12∆Prrx1 mice was dramatically increased, as evidenced by a more than twofold increase in several osteoblast- and osteoclast-specific mRNAs, as well as increased mineral apposition and bone formation rate and increased osteoclast number in the endosteal surface. The magnitude of the Cxcl12∆Prrx1 -induced changes were much greater than those caused by ovariectomy or orchidectomy in the Cxcl12f/f mice. These results strengthen the evidence that CXCL12 contributes to the loss of cortical bone mass caused by estrogen deficiency. Moreover, they reveal for the first time that in addition to its effects on hematopoiesis, CXCL12 restrains bone turnover-without changing the balance between resorption and formation-by suppressing osteoblastogenesis and the osteoclastogenesis support provided by cells of the osteoblast lineage. © 2020 American Society for Bone and Mineral Research.

CLINICAL EFFECTS OF HUMAN IMMUNOGLOBULIN ADMINISTRATION IN WOMEN WITH RHESUS SENSITIZATION AT THE PRE-GRAVID STAGE

The aim of the study – to evaluate changes in cellular immunity in rhesus-sensitized women in response to IVIG administration and the prognostic effectiveness of a method for the prevention of isoimmunization in the next pregnancy.
 Materials and Methods. The study was performed on the basis of City Maternity Hospital No. 7" (Odesa) in 2014–2019. 37 rhesus-sensitized women were randomly splited in two clinical groups: main clinical group (n=19) where patients received human immunoglobulin for intravenous administration, and control group (n=18) where patients did not receive IVIG.
 Results and Discussion. The state of cellular immunity in rhesus-sensitized women is characterized by a moderate decrease in the absolute and relative indices of T-lymphocytes while increasing the number of B-lymphocytes. The NK cell population did not differ from the control group. When analyzing subpopulations of T-lymphocytes, it can be concluded that the number of T-helper cells is increased and the number of T-suppressors is proportionally reduced. These changes explain the increase in the number of B-lymphocytes as a result of increasing antigenic load on cell receptors. In the group of women who received IVIG therapy, the ratio of chances of normalization of cellular immunity was 18.41 (95 % CI 2.62–166.74), T-helper – 14.93 (95 % CI) 2.45–107.8), T-suppressors – 14.57 (95 % CI 2.13 –127.57) and B-lymphocytes – 31.87 (95 % CI 4.1–333.41). According to the ROC analysis, the quality of the statistical model of IVIG application corresponds to AUC = 0.843 (95 % CI 0.689–0.941) According to the ROC analysis, the level of β-lymphocytes in the compared AUC groups = 0.58 (95 % CI 0.405–0.742).

The Impact of Chemotherapy after Pediatric Malignancy on Humoral Immunity to Vaccine-Preventable Diseases.

Background/AimThe antibody titer of vaccine-preventable diseases in pediatric patients who underwent chemotherapy was assessed in order to evaluate the seroprotection after treatment and the feasibility and the efficacy of a policy of revaccination.MethodsSerum antibody titers of 55 patients for hepatitis B (HBV), rubella, varicella-zoster (VZV), measles, mumps, polio viruses, Clostridium tetani (C. tetani) and Streptococcus pneumoniae (S. pneumoniae) were analysed.Results: After chemotherapy, a lack of protective antibody titers against HBV, rubella, VZV, measles, mumps, polio viruses, C. tetani, and S. pneumoniae was found in 53%, 45%, 46%, 46%, 43%, 21–26%, 88% and 55% of patients, respectively. In 49 of 55 patients who were tested both before and after chemotherapy for at least a pathogen, the loss of immunity for HBV, rubella, VZV, measles, mumps, polio viruses and C. tetani was respectively 39%, 43%, 38%, 42%, 32%, 33%, and 80%. A low number of B-lymphocytes was associated with the loss of immunity against measles (p=0.04) whereas a high number of CD8+ T-lymphocytes was associated with the loss of immunity against VZV (p=0.03). A single booster of vaccine dose resulted in a seroprotection for HBV, rubella, VZV, measles, mumps, polio viruses, C. tetani and S. pneumoniae in 67%, 83%, 80%, 67%, 33%, 100%, 88% and 67% of patients, respectively.ConclusionsWe confirm that seroprotection for vaccine-preventable diseases is affected by treatment for pediatric malignancy. A single booster dose of vaccine might be a practical way to restore vaccine immunity in patients after chemotherapy.

Characterization of B1-cells during experimental leukomogenesis.

Bovine leukemia causes a significant polyclonal expansion of CD5+, IgM+ B lymphocytes, known as persistent lymphocytosis (PL), in approximately 30% of infected cattle. However, it is not yet clear what happens to this subpopulation of B cells in the early period of infection of animals. Quantitative characterization of IgM+ and CD5+ B cells during the immune response, which can provide important information on the mechanisms of lymphocyte priming in BLV infection. The experiment used BLV-negative calves of black-motley breed at the age of 8 months (n = 11). Animals (n = 8) were intravenously injected with blood of a BLV-positive cow. Control calves (n = 3) were injected with saline. Studies were performed before and after infection on days 5, 7, 14, 21, 28 and 65 of the immune response. The determination of the number of B-lymphocytes in the blood was carried out by the method of immunoperoxidase staining based on monoclonal antibodies to IgM, CD5. As a result of the studies, it was found that the level of CD5+ B cells increases on the 14th day of the primary immune response, characterized by polyclonal proliferation of CD5+ B cells, which are the primary target for BLV. Our research data confirm that in the lymphocytes of experimentally infected cattle, surface aggregation of IgM and CD5 molecules on B-lymphocytes is absent. It is known that the wave-like nature of IgM synthesis, which was shown in previous studies, depends on a subpopulation of B1 cells. After 7 days of the immune response, IgM+ and CD5+ cells do not correlate, which shows their functional difference. The increase in CD5+ cells is probably not associated with B cells, but with T cells differentiating under the influence of the virus. A subset of B1 cells is the primary target of cattle leukemia virus. The 65th day of the immune response is characterized by the expansion of IgM+ B cells, a decrease in the number of CD5+ cells and a uniform distribution of receptors around the perimeter of the cells.

47. A case of pulmonary lymphomatoid granulomatosis diagnosed on needle core biopsy

Background: Lymphomatoid granulomatosis (LYG) is a rare extranodal lymphoproliferative disorder composed of B cells positive for Epstein-Barr virus (EBV) and reactive T cells. It has a variable clinical course ranging from spontaneous remission to aggressive lymphoma with high mortality. Aims: We present a case of solitary pulmonary lymphomatoid granulomatosis in an asymptomatic, seemingly immune competent female with a distant history of breast cancer. Methods: The patient had initially presented two years earlier with radiographic evidence of multiple hepatic nodules and a single upper lobe lung lesion presumed to be disseminated metastasis; however, interval imaging showed spontaneous resolution. Two years after the initial presentation, the patient represented systemically unwell and underwent a lung needle core biopsy for a left upper lobe cavitating intensely avid lesion found on CT imaging. Results and conclusion: Histologically, the core biopsies revealed a large area of coagulative necrosis with an atypical mixed inflammatory cell infiltrate demonstrating both angiocentric and angiodestructive features. The cellular infiltrate included small lymphocytes, large atypical lymphoid cells and abundant histiocytes with vague granuloma formation. On immunohistochemistry the large atypical cells were positive for CD20 and PAX5 with in situ hybridisation confirming the presence of EBER. The patient was subsequently diagnosed with lymphomatoid granulomatosis favoured to be a grade 3 due to the numbers of atypical B-cells and extensive necrosis. In conclusion, we report a rare case of relapsing nodular lesions of the lung and liver, which after two years showed diagnostic features of lymphomatoid granulomatosis. The lung lesion was unusual being a large solitary mass. Combination chemotherapy with rituximab has led to a complete and metabolic (PET) response and remission to date.